The chronic renal disease and renal failure which derives therefrom are extremely frequent diseases even though under-diagnosed; actually, it is estimated that 17% of the adult population is affected by this disease.
The most frequent renal disease is characterised by damaged renal glomeruli.
Renal diseases may be congenital or acquired; in particular the acquired ones may have various etiology:                immunologic like the Goodpasture's syndrome, lupus nephritis and immunoglobulin A nephropathy. In the case of the immunologically mediated renal disease, the cause lies in the presence of a strong antigenic stimulus which triggers an immune reaction;        dysmetabolic and in particular diabetic nephropathy, one of the most common causes of chronic renal disease. The prevalence is of 20-30% in patients suffering from type 1 diabetes and about 10% of the cases in patients suffering from type 2 diabetes. This is an insidious disease in that it is characterised by a particularly slow occurrence (up to 20-30 years from the occurrence of diabetes) and it is practically asymptomatic over a long period of time; it initially occurs through a microalbuminuria (an amount of albumin in the urine comprised between 30 and 300 mg/l) which slowly develops into macroalbuminuria indicating a manifest nephropathy (an amount of albumin in the urine exceeding 300 mg/l, up to reaching values of 3 g within 24 hours);        hemodynamic, due to arterial hypertension. An alteration in the pressure mechanisms of the renal blood flow leads, over time, to a reduction of the renal filtering capacity;        ischemic. Renal ischemia is the most frequent pathogenic event involved in acute renal disease and in the ensuing tubular necrosis, both in native and transplanted kidneys;        toxic. Most of the clinically important drugs (cytotoxic agents, chemotherapy agents, nonsteroidal anti-inflammatory drugs, corticosteroid therapies, etc) and various chemical products (such as radiologic contrast media, solvents, etc) produce nephrotoxicities capable of very frequently causing inflammation at the renal parenchymal level and functional insufficiency both transitory and chronic.        
Even in veterinary medicine, renal diseases bound to develop into chronic renal disease constitute an important clinical category, representing the second cause of death in dogs, after diseases of tumour origin, and the first cause of death of the aged cats. From an etiologic point of view, the causes that determine the loss, progressive and irreversible, of the functionality of the nephrons in small animals were precisely classified in (Squires et al, 1998) in:                Degenerative: chronic interstitial nephritis; renal infarction        Autoimmune: Anti-GBM glomerulonephritis        Metabolic: diabetes; hyperthyroidism (cats); hypercalcemia        Neoplastic: renal lymphomas and carcinomas        Idiopathic: amyloidosis; idiopathic glomerulonephritis        Infective: bacterial pyelonephritis; Lyme nephropathy (Borreliosis)        Immune-mediated: immune-complex glomerulonephritis        Toxic: nephrotoxic drugs (e.g. cisplatin, aminoglycosides, NSAIDs)        Traumatic: rupture of bladder and urethra.        
In any case, regardless of the etiology, in all acquired renal diseases, both in humans and animals, there is an activation of the inflammatory processes primarily aimed at countering the harmful events but which may become the cause of renal glomerulosclerosis and of tubulointerstitial fibrosis capable of determining the development of chronic renal disease up to the pre-End stage (pre-End Stage Renal Disease) wherein most of the nephrons are destroyed. One of the two main objectives of nephrology is, first and foremost, that of understanding the mechanism which regulates the passage from an acute renal damage to the chronic fibrotic renal disease given that, once the fibrogenesis has started it might be very difficult, currently, to intervene on the fibrotic process; in any case, the objective of stopping or at least slowing the progression of the chronic renal disease remains extremely important considering that such disease also constitutes an important risk factor for cardiovascular diseases. Regarding this, currently there are several studies aimed at accurately understanding the most significant mechanisms of occurrence, with the aim of preventing the phenomena that determines the irreversibility of the disease. Among these phenomena, the most significant one is that which induces tubulointerstitial fibrosis considered the main cause of the chronic renal disease; fibrosis causes an excessive accumulation of extracellular type, mainly made up collagen, and it is usually accompanied by a progressive loss of renal function when the normal tissue is replaced by a cicatricial tissue. One of the most currently studied phenomena is constituted by processes of controlling the genesis of mio-fibroblasts and by the role played by these cells in the formation of the fibrotic cicatricial tissue. In particular such studies try to understand the reason why a reparative phenomenon usually provided for by the tissue, like the renal one, continuously subjected to an extensive amount of noxae, may at one point determine an excessive increase of the extracellular matrix and thus a tubulointerstitial fibrosis. Particular attention is currently paid to the genesis of mio-fibroblasts both starting from tubular-epithelial cells and from endothelial cells through a process of phenotypic transformation from epithelial to mesenchymal, potently stimulated by the TGF-1β (Transforming Growth Factor). Actually, the TGF-1β expression constantly increases in the renal tubular epithelium during an active process of fibrogenesis. In animal models of renal damage, the dose in the renal tubular epithelium of the TGF-1β is considered an interesting indication of the state of activation of fibrogenesis and, hence the state of functional alteration induced by the renal disease.
Regardless of the extensive new information regarding the pathogenic mechanisms involved in the development of renal diseases, satisfactory therapeutic solutions for controlling these conditions are yet to be discovered.
Palmitoylethanolamide (PEA) is the parent of a family of N-acyl amides called Aliamides: a class of endogenous lipid molecules capable of normalizing the activity of immune cells through a local antagonist mechanism. The analgesic effects, instead, are related to a normalisation of the controlled release of trophic factors like NGF which, if present in excess in the tissues, make the neuronal structures hypersensitive and hyperexcitable, with the occurrence of hyperalgesia and allodynia. From a clinical point of view, the oral uptake of products containing PEA is capable of improving the neuropathic symptomatology related to the peripheral neuropathy also promoting the functional recovery of the motor conduction velocity. PEA, at experimental level, is also efficient in dysmetabolic neuropathies, in particular administration thereof to animals made diabetic with streptozotocin eliminates allodynia and induces a partial recovery of the body weight and an increase of the insulin blood levels. These animals also reveal low over-production of blood free radicals and the levels of NGF in the sciatic nerve.
Analogously to the PEA, given N-acyl amides, generally formed from monoethanolamine and dicarboxylic fatty acids, saturated and unsaturated, per se non-physiologic but equally capable of forming, during catabolism, substances physiologically present in the organism of mammals, thus not determining accumulation and/or toxicity of any kind, proved capable of determining pharmacological effects similar to the parent PEA.